Mill for preparing cocoa, &amp;c.



No. 797,665. PATENTED AUG. 22, 1905.

F. P. CROFT.

MILL FOR PREPARING COCOA, &o.

APPLICATION FILED APR.'I, 1902.

monaw. a, 0mm 00, wom-umoummws. waswasvm J c PATENTED AUG. 22, 1905.

F. P. CROFT.

MILL FOR PREPARING COCOA, &c.

APPLICATION FILED APR.7, 1902.

3 SHBETSSHBET 2.

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No. 797,665 v PATBNTED AUG. 22, 1905.

. F. P. CROFT. MILL FOR PREPARING 0060A, &0.

APPLICATION FILED APRJ, 1902.

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FRANK P. CROFT, OF MERION, PENNSYLVANIA.

lVllLL FOR PREPARING COCOA, &c.

Specification of Letters Patent.

' Patented Aug. 22, 1905.

Application filed April 7, 1902. Serial No. 101,642.

To (tZZ whom, it natty concern.-

Be it known that I, FRANK P. Caon'r, a citizen of the United States,residing in Mei-ion, county of Montgomery, State of Pennsylvania, haveinvented certain new and useful Improvements in Mills for PreparingCocoa, &c., of which the following is a specification, reference beinghad to the accompanying drawings, forming a part hereof.

In the preparation of cocoa for the market as heretofore carried on muchdifficulty has been experienced in the reduction of the cocoa to thedesired degree of fineness. Usually after grinding the cocoa has beenpassed through sieves in order to separate that portion which has beenreduced to the desired fineness from that portion which must bereground; but the sifting of the cocoa in this manner is necessarilyslow, the sieves quickly choke up with particles of cocoa, and the cocoaitself suffers undesirable changes in color, which sometimes affect itsmarket value.

It is the object of this invention to provide for the rapid reduction ofcocoa to the desired degree of fineness without passing it throughsieves and without permitting it to heat or otherwise to suffer anychange in quality or color during reduction.

In the improved mill or apparatus the cocoa, immediately after beingground, is subjected to the action of a blast of air which serves toseparate that portion which is sufficiently fine from that portion whichrequires further grinding, cools the particles of cocoa as they comefrom the grinder, preventing any change in color or quality, anddistributes the finely-ground cocoa so that no heating can occur.

It will be obvious that the invention is applicable to other particularuses than the preparation of cocoa, and although the primary object ofthe invention is to improve the preparation of cocoa nevertheless itwill be understood that the invention is not necessarily restricted tothe treatment of this particular substance.

The invention will be more fully described hereinafter with reference tothe accompanying drawings, in which for purposes of illustration andexplanation the apparatus is shown in a convenient and practical form,which has been found to operate satisfactorily.

In the drawings, Figure l is a view in side elevation of the apparatus.Fig. 2is a longitudinal section on an irregular vertical plane. Fig. 3is an end elevation of the apparatus as seen from the right in Fig. 1.Figs. at and 5 are detail views, on a larger scale, illustratingparticularly the'means for regulating the blast of air. Fig. 6 is adetail view, also on a larger scale, of the device for adjusting thetension of the conveyer.

The apparatus shown in the drawings is so designed that thefreshly-ground cocoa shall be struck by a blast of air which carries itforward into a suitable settling or collecting chamber that which issufficiently fine, while the remaining portion is returned to bereground.

The apparatus comprises a suitable grinder, means for directing a blastof air upon the freshly-ground material, a settling or collectingchamber, and suitable conveyers for handling the material. It will beobvious that these parts may be variously arranged and that, if sodesired, the grinding might be effected by a separate machine; but forconvenience and rapid action the several parts are preferably combinedin one apparatus.

Any suitable grinder may be employed, that represented in the drawingsbeing Well adapted for the purpose. It comprises a series of circularsaws, one of which is represented at a, mounted upon a common shaft a,the gang of saws being incloscd in a suitable casing 6, provided with afeeding-hopper b, the hopper being reciprocated by any suitable means,as by a crank 6 From the grinder the cocoa or other material falls intoa chute c, the opening 0 being preferably at a short distance from theend of the chute, which is itself preferably inclined upward,substantially represented. Provision is made for the introduction of ablast of air at the lower end of the chute, the means shown consistingof a blower (Z, connected by a suitable pipe d with the lower end of thechute, which is provided with ways (2 for the reception of a diaphragm(Z Several such diaphragms having openings of different sizes areprovided, so that the blast of air may be regulated according to theresults to be produced. Within the chute c is provided a conveyer, whichmay consist of suitable sprocket-wheels e, mounted upon shafts e, one ofwhich, preferably the lower one, is the driver, endless chains 0, andblades 1: carried thereby. The upper shaft 0 is preferably carried by anadjustable bearing a", as shown in Figs. 1 and 6, so that the tension ofthe chains may be adjusted. The conveyor is driven in such a directionthat the blades 0, which are in conupon all parts of the floor.

tact with the lower side of the chute 0, shall travel downward or in adirection opposite to that of the blast of air for the purpose ofcarrying backward through the chute the larger particles of cocoa whichare deposited on the bottom of the chute and should be ground finerbefore being discharged into the receiving or collecting chamber, intowhich those particles which are sufficiently fine are carried by theblast of air. It will be obvious that by regulating the blast of aironly those particles which have the desired fineness will be carriedthrough the chute, all other particles being retained by the conveyer.

The receiving, settling, or collecting chamher, into which the finematerial is discharged from the chute by the blast of air, is suitablyconstructed for the collection of the material and for the release ofthe air without loss of the material. For this purpose the walls of thechamber are made of muslin, (indicated at 1",) through which the air mayescape while the fine material is retained, the muslin being supportedby a suitable framework, (indicated at f.) The chamber is preferablyprovided with a horizontal partition in which is formed a substantiallycentral opening The greater part of the fine material settles upon theintermediate floor or partition f upon which it is evenly distributed,so that there is no liability of heating in any one part, with aconsequent change in color or quality of a portion of the material.Below the opening f may be placed a tank g, in which some of thematerial is deposited by the blast of air and into which so much of thematerial as collects upon the intermediate fioor or partition f may begathered when the operation of the apparatus is temporarilydiscontinued. A door f is provided to give access to the upper part ofthe chamber and another door f to give access to the lower part of thechamber and to permit the tank g to be introduced and withdrawn. In somecases or under some conditions it is found that more or less backpressure is developed if the chamber is constructed as already describedand that the material does not settle uniformly To obviate thesedifficulties, an auxiliary chamber it is provided, the same beingconstructed in substantially the same manner as the main chamber withwalls it of muslin supported by a suitable framework. This auxiliarychamber communicates, through an opening at if, with the lower part ofthe main chamber and also through an opening at b with the upper part ofthe main chamber, so that the current of air within the chambers followsthe general line indicated by the arrows in Figs. 1 and 2. With thisarrangement it is found that practically no back pressure is developedand that the material is deposited uniformly without excessiveaccumulations at any one point.

The heavier material, which is returned through the chute 0, isdischarged therefrom through an opening 0 in thelower side thereof andnearer the lower end of the chute than the openingc. The coarsermaterial which must be reground falls through the opening 0 into areceiver a, from which it is conveyed, preferably, by a screw conveyer]t' into the pit of an elevator-shaft Z, in which is disposed a verticalconveyer which may consist of an endless chain Z', carried by suitablesprocketwheels Z and provided with suitable buckets Z. The elevatordischarges the material into areceiver m, in which may be disposedascrew conveyer n to transfer the material to a chute m, by which it isdischarged into the hopper 7) of the grinder. By locating the openings 6and c substantially as shown in Fig. 2 the proper action of the blast ofair upon the freshlyground material is secured without creating undueback pressure in any part of the mechanism.

It is sometimes the case that the material to be treated is brought tothe apparatus so finely broken up as to make it inconvenient to placethe same in the hopper Z) of the grinder. Accordingly a receptacle 0 isprovided for material in such condition, and in the bottom thereof maybe disposed a screw conveyer p, by which the material is transferred tothe pit of the elevator-shaft, to be thence conveyed by the elevator andthe conveyer n to the hopper .7).

The mode of operation of the apparatus and the method of treating thecocoa or other material will now be readily understood. Having beenground or otherwise broken up, the material is struck by the blast ofair which may be regulated in temperature according to the prevailingconditions as well as in intensity or volume, and the material isimmediately brought to the proper temperature, whether the same behigher or lower, and is carried upward through the chute, the coarserparticles being deposited on the way to be returned for further grindingor breaking up, while the particles sufliciently fine are dischargedinto the receiving-chamber and are then distributed uniformly, so thatthere shall be no excessive accumulations at any point, and consequentlyno heating of the material. hen the material has accumulated in thereceiving-chamber in the desired quantity, the operation is discontinuedand the material is either collected at once or allowed to remain spreadout on the floor of the receiving-chamber until it can be safelygathered in the tank without danger of heating. It will be found that bythis method of treatment and with such an apparatus as that describedthe fine cocoa or other material will be uniform in color and qualityand will have suffered no injurious change.

It will be obvious that the apparatus for conveniently andadvantageously treating the material may be varied in the constructionand arrangement of its several parts without departing from the spiritof the invention.

I claim as my invention 1. An apparatus for treating cocoa or othermaterial comprising an inclined chute, means for delivering the groundor broken-up material into the chute, near its lower end, means forsupplying a blast of air against the material as it is delivered to thechute to carry the finer particles forward in the chute, areceiving-chamber arranged to receive the particles carried by theair-blast and to permit the air to escape, and a positively-actingconveyer within the chute arranged to move the heavier particles alongthe chute in a direction contrary to the direction of the air-blast;substantially as described.

2. An apparatus for treating cocoa or other material comprising aninclined chute, means for delivering ground or broken-up material intothe chute near its lower end, means for supplying a blast of air againstthe material as it is delivered to the chute to carry the finerparticles forward in the chute, a receivingchamber arranged to receivethe particles carried by the air-blast and to permit the air to escape,and a conveyer comprising an endless chain carrying blades, locatedwithin the chute and arranged to positively act upon the heavierparticles to move them along the chute in a direction contrary to thedirection of the air-blast; substantially as described.

3. An apparatus for treating cocoa or other material com prising aninclined chute, means for delivering ground or brokenup material intothe chute, means for supplying a blast of air against the material as itis delivered to the chute to carry the liner particles forward in thechute, a receiving-chamber arranged to receive the particles carried bythe air-blast and to permit the air to escape, and a con veyer locatedWithin the chute comprising an endless chain carrying blades arranged tocontact with the lower side of the chute and positively act upon theheavier particles to move them along the chute in a direction contraryto the direction of the air-blast; substantially as described.

4. An apparatus for treating cocoa or other material comprising agrinder, a chute into which the freshly ground material is dischargedfrom the grinder, means for discharging a blast of air against thefreshly-ground material to carry the material forward in the chute, thechute being of such length that the coarser particles of the groundmaterial will be deposited therein, means for removing the coarserparticles from the chute and returning them to the grinder, and areceivingchamber into which the finer particles of the ground materialare carried by the blast of air and from which the air may escape;substantially as described.

5. An apparatus for treating cocoa or other material comprising agrinder, a chute into which the freshly ground material is dischargedfrom the grinder, means for discharging a blast of air against thefreshlyground material to carry the material forward in the chute, thechute being of such length that the coarser particles of the groundmaterial will be deposited therein, a traveling conveyer in said chutearranged to move the coarser particles deposited in the chute in adirection contrary to the direction of the blast of air, means forconveying the coarser particles to the grinder and the receivingchamberinto which the finer particles are carried by the blast of air, and fromwhich the air may escape; substantially as described.

6. An apparatus for treating cocoa and other material comprising agrinder, an inclined chute into which the freshly-ground material isdischarged from the grinder, means for discharging a blast of airagainst the freshlyground material to carry the material forward in thechute, the chute being of such length that the coarser particles of theground material will be deposited therein, a traveling conveyer in thechute arranged to move the coarser particles deposited in the chute in adirection opposite to the direction of the blast of air, an elevator andconveyer for returning the coarser particles to the grinder, and areceiving-chamber into which the finer particles of the ground materialare carried by the blast of air and from which the air may escape;substantially as described.

7. An apparatus for treating cocoa or other material comprising agrinder, a chute having an opening through which the material from thegrinder is discharged, means to discharge a blast of air against thefreshly-ground ma terial to carry the material forward in the chute, areceiving-chamber into which the finer particles are carried by theblast of air and from which the air may escape, the chute having in itsunder side, near the entrance of the air-blast, an opening fordischarging the coarser particles, positive means for moving the coarserparticles along said chute in a direction opposite to the direction ofthe blast of air toward said second opening and means to return suchcoarser particles from said sec- "ond opening to the grinder;substantially as described.

8. An apparatus for treating cocoa or other material comprising a chute,means for delivering ground or broken-up material to the chute, meansfor discharging a blast of air against such material, and areceiving-chamber into which the liner particles are carried by theblast of air and from which the air may escape, said chamber having anintermediate floor or horizontal partition below the level at which theblast of air enters the chamber, to receive such liner particles, suchfloor or horizontal partition being formed with an opening through whichthe air may pass freely; substantially as described.

9. An apparatus for treating cocoa or other I with an opening throughwhich the air may pass freely, and an auxiliary chamber communicatingwith the upper and lower portions of the first-named chamber;substantially as described.

This specification signed and witnessed this 2d day of April, A. D.1902.

FRANK P. CROFT.

In presence of- EDWIN F. ROBERTS, R. S. REED.

